T regulatory cells suppress immune responses of other cells. They come in several forms with the most well-understood being those that express CD4, CD25, Foxp3, and Helios (CD4+CD25+ Tregs). These cells are involved in shutting down immune responses after they have successfully eliminated invading organisms, and in preventing autoimmunity. Methods for expanding non-specific regulatory T cells have been described in the literature. However, because the T cells employed in those methods were non-specific, the activity of such cells could be immunosuppressive for responses to pathogenic infections and cancer, where an immune response would be desirable.
There currently exists a need for effective therapies to minimize or eliminate the undesirable immune response to self components that is the underlying cause of autoimmune disorders, including type 1 diabetes, uveitis and multiple sclerosis, and the unfavorable response to treatment of genetic diseases like hemophilia and Pompe's with biotherapeutics.